Articulatable surgical instruments with separate and distinct closing and firing systems

ABSTRACT

A surgical instrument that has an articulatable end effector that includes a second jaw that is selectively moveable in a first direction relative to a first jaw upon application of a closing motion to the second jaw from a closure system and is further movable in a second direction relative to the first jaw upon application of an opening motion to the second jaw from the closure system. An elongated shaft assembly is coupled to the end effector and defines a longitudinal tool axis. The end effector is selectively articulatable in the first and second directions relative to the longitudinal tool axis upon application of articulation motions to the end effector. The end effector may include a firing member that is operable in response to firing motions applied thereto from a firing system. The closing system and firing system may be selectively independently operable from each other.

BACKGROUND

The present invention relates to surgical instruments and, in various embodiments, to surgical cutting and stapling instruments and staple cartridges therefor that are designed to cut and staple tissue.

BRIEF DESCRIPTION OF DRAWINGS

The various features and advantages of this invention and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of one surgical instrument arrangement;

FIG. 2 is an exploded perspective assembly view of a surgical end effector arrangement;

FIG. 3 is a side elevational view of an anvil;

FIG. 4 is a side cross-sectional view of an end effector and portion of an elongated shaft assembly with the end effector shown in an unarticulated position in solid lines and the end effector shown in articulated positions in broken lines;

FIG. 5 is another side cross-sectional view of an end effector and portion of an elongated shaft assembly with the anvil in a closed position and the cutting head in an end position after being fired distally through the staple cartridge;

FIG. 6 is another side cross-sectional view of the end effector and elongated shaft assembly portion of FIG. 5 after the cutting head has been retracted proximally back to its starting position;

FIG. 7 is another side cross-sectional view of an end effector and portion of an elongated shaft assembly with the anvil in an open position and the cutting head in a starting position;

FIG. 8 is an enlarged cross-sectional view of the end effector and portion of the elongated shaft assembly of FIG. 7;

FIG. 9 is cross-sectional perspective view of the end effector and portion of the elongated shaft assembly of FIG. 8;

FIG. 10 is a perspective assembly view of an end effector and elongated shaft assembly;

FIG. 11 is a cross-sectional view of a distal portion of an elongated shaft assembly;

FIG. 12 is a cross-sectional view of a proximal portion of the elongated shaft assembly of FIG. 11 along with a portion of an articulation system;

FIG. 13 is a perspective view of an elongated shaft assembly and end effector; and

FIG. 14 is a partial perspective exploded view of a handle assembly.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate preferred embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

Applicant of the present application also owns the following patent applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:

-   -   U.S. patent application entitled: “Surgical Staples and Staple         Cartridges”, Attorney Docket No. END7341USNP/130301;     -   U.S. patent application entitled: “Surgical Staples and Staple         Cartridges”, Attorney Docket No. END7331USNP/130304:     -   U.S. patent application entitled: “Surgical Staples and Methods         For Making the Same”, Attorney Docket No. END7335USNP/130305;     -   U.S. patent application entitled: “Surgical Staples, Staple         Cartridges and Surgical End Effectors”, Attorney Docket No.         END7332USNP/130306;     -   U.S. Design patent application entitled: “Surgical Fastener”,         Attorney Docket No. END7338USDP/130307;     -   U.S. patent application entitled: “Fastener Cartridge Comprising         an Extendable Firing Member”, Attorney Docket No.         END7344USNP/130308;     -   U.S. patent application entitled: “Fastener Cartridge Comprising         a Firing Member Configured to Directly Engage and Eject         Fasteners From the Fastener Cartridge”, Attorney Docket No.         END7339USNP/130309;     -   U.S. patent application entitled: “Fastener Cartridge Comprising         a Firing Member Including Fastener Surfaces”, Attorney Docket         No. END7340USNP/130310;     -   U.S. patent application entitled: “Surgical Instruments With         Articulatable Shaft Arrangements”, Attorney Docket No.         END7343USNP/130300;     -   U.S. patent application entitled: “Surgical Cutting and Stapling         Instruments With Independent Jaw Control Features”, Attorney         Docket No. END7336USNP/130303;     -   U.S. patent application entitled: “Surgical Cutting and Stapling         Instruments With Articulatable End Effectors”, Attorney Docket         No. END7334USNP/130312;     -   U.S. patent application entitled: “Surgical Cutting and Stapling         Methods”, Attorney Docket No. END7330USNP/130313; and     -   U.S. patent application entitled: “Modular Surgical         Instruments”, Attorney Docket No. END7342USNP/130311.

Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.

Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment”, or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present invention.

The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the person of ordinary skill in the art will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, those of ordinary skill in the art will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced.

Turning to the Drawings wherein like numerals denote like components throughout the several views, FIG. 1 depicts a surgical instrument 10 that is capable of practicing several unique benefits of the present invention. The surgical instrument 10 is designed to manipulate and/or actuate various forms and sizes of end effectors 12 that are operably attached to an elongated shaft assembly 100 of the surgical instrument. In the depicted embodiment, for example, the end effector 12 comprises a surgical stapling device that has openable and closable jaws 13 and 15. More specifically, the end effector 12 includes an elongated channel 14 that forms a lower jaw 13 of the end effector 12. See FIG. 2. In the illustrated arrangement, the elongated channel 14 is configured to operably support a staple cartridge 30 and also movably supports an anvil 20 that functions as an upper jaw 15 of the end effector 12.

Referring now to FIGS. 2 and 3, the anvil 20 may have a mounting portion 22 that protrudes from its proximal end 21. The mounting portion 22 may have lateral mounting holes 24 therethrough that enable the mounting portion 22 to be pivotally pinned to an upstanding pivot boss 17 formed in the elongated channel 14 by an anvil pin 18. The anvil 20 may be selectively “moved” towards the surgical staple cartridge 30 mounted in the elongated channel 14 by axially advancing a distal closure tub segment 190 in the distal direction “DD” as will be discussed in further detail below. In various implementations, for example, a first anvil actuation member in the form of an anvil camming pin 19 may extend through a camming slot 23 provided in the anvil mounting portion 22. The camming pin 19 is mounted in holes 191 provided in the distal closure tube segment 190 such that movement of the distal closure tube segment 190 in the distal and proximal directions will result in the movement of the camming pin 19 in the camming slot 23. In addition, the distal closure tube segment 190 may further include a second anvil actuation member in the form of, for example, an actuation pin 193 that is positioned to interact with an angled actuation surface 25 formed on the proximal end of the anvil mounting portion 22. FIGS. 7-9 illustrate the anvil 20 in a first or open position. The anvil 20 may be moved to a closed position by moving the distal closure tube segment 190 in the distal direction “DD”. Movement of the distal closure tube segment 190 in the distal direction “DD” causes the first camming pin 19 to move within the camming slot 23 in the anvil mounting portion 22 which thereby causes the anvil 20 to pivot about the anvil pin 18 to the closed position as illustrated in FIGS. 4-6. To return the anvil 20 to the open position (FIGS. 7-9), the distal closure tube segment 190 is moved in the proximal direction “PD” which causes the first camming pin 19 to move in the camming slot 23 in an opposite direction and cam the anvil 20 to the open position. Such closure tube arrangement differs from prior closure tube arrangements wherein the distal end of the closure tube segment is configured to contact the anvil and pivot it to a closed position. Use of the present camming pin arrangements does not require use of an anvil that has a more robust portion configured for actuation contact with the closure tube segment.

In various arrangements, the end effector 12 may be configured to be selectively articulated about a longitudinal tool axis LT-LT that is defined by the elongated shaft assembly 100. For example, the elongated shaft assembly 100 may include a flexible neck assembly 110 that enables the end effector 12 to articulate in a first direction “FD” that is essentially the same direction that the anvil 20 moves in when the anvil 20 is moved from an open position to a closed position (hereinafter referred to as the anvil closing direction “CD”). See FIGS. 4 and 8. The flexible neck assembly 110 will further facilitate articulation of the end effector 112 in a second articulation direction “SD” that is essentially the same as the direction that the anvil moves from a closed position to an open position (hereinafter referred to the anvil opening direction “OD”). See FIGS. 4 and 7.

Various flexible neck assemblies are disclosed in U.S. Provisional Patent Application Ser. No. 61/386,117, filed Sep. 24, 2010, the entire disclosure of which is herein incorporated by reference. Other flexible neck assemblies are disclosed in U.S. Patent Application Publication No. US 2012/0074200 A1, entitled SURGICAL INSTRUMENT WITH SELECTIVELY ARTICULATABLE END EFFECTOR, filed Sep. 23, 2011, the entire disclosure of which is hereby incorporated by reference herein. The flexible neck assembly 110 may, for example, be composed of rigid thermoplastic polyurethane sold commercially as ISOPLAST grade 2510 by the Dow Chemical Company. The flexible neck assembly 110 may have a flexible neck segment 111 that comprises a first or upper flexible neck portion 112 and a second or lower flexible neck portion 114. These neck portions 112, 114 may be separated by a longitudinal rib portion 116. The neck portions 112, 114 may each have a plurality of neck ribs 118 that are configured essentially as semi-circular disks which together generally form a cylindrical configuration. An upper slot 120 extends through each of the neck ribs 118 of the first or upper flexible neck portion 112 to form a passage through the first flexible neck portion 112 for receiving a first flexible transmission band assembly 150 therethrough. Similarly, a lower slot 121 extends through each of the neck ribs 118 in the second or lower flexible neck portion 114 to form a passage for receiving a second flexible transmission band assembly 170 therethrough. See, for example, FIG. 4. The flexible neck assembly 110 may include guide surfaces 124 (only one can be seen in FIG. 10) that extend proximally from the flexible neck segment 111 for supporting the reciprocating movement of the flexible transmission band assemblies 150, 170.

As can be seen in FIG. 10, the first or upper transmission band assembly 150 may include a first transmission band 152 and the second transmission band assembly 170 may include a second transmission band 172. In addition, the first transmission band 150 may have a first elongated structural portion 154 and the second transmission band 170 may have a second elongated structural portion 174. When the first and second transmission bands 150, 170 are brought into contact with each other during assembly of the instrument, they form an elongated cylinder which has a longitudinal cavity 160 extending concentrically through it to operably receive a firing rod 530 therethrough. See FIGS. 11 and 12. The first structural portion 154 of the first transmission band 152 has a first articulation rack 156 formed thereon and the second structural portion 174 of the second transmission band 172 has a second articulation rack 176 formed thereon which, as will be discussed in further detail below, drivingly interface with an articulation transmission assembly 200.

Referring again to FIG. 10, the first transmission band 152 may have a first exterior reinforcement band portion 157 that extends distally from the first structural portion 154. Likewise, the second transmission band 172 may have a second exterior reinforcement band portion 177 that extends distally from the second structural portion 176. Each exterior reinforcement band portion 157, 177 may have a plurality of attachment lugs 162 for securing first and second interior articulation bands 158, 178 thereto. For example, the first transmission band 152 has a first interior articulation band 158 attached thereto and the second transmission band 172 has a second interior articulation band 178 attached thereto. The first and second transmission bands 152, 172 may be composed of a plastic, especially a glass fiber-reinforced amorphous polyamide, sold commercially under the trade name Grivory GV-6H by EMS-American Grilon. In contrast, the interior articulation bands 158, 178 of the transmission band assembly may be composed of a metal, advantageously full hard 301 stainless steel or its equivalent. The attachment lugs 162 on the exterior reinforcement band portions 157, 177 of the transmission bands 152, 172, respectively, are received into and secured within a plurality of lug holes 164 on the corresponding interior articulation band 158, 178. See FIG. 10.

In at least one implementation, the proximal end of the elongated cartridge channel 14 is provided with a pair of upper and lower band connector ears 50. See FIGS. 2 and 4-8. These band connector ears 50 are inserted into and through connector loops 159, 179 on the distal end of the interior articulation bands 158, 178, respectively. In this manner, the cartridge channel 14 is coupled to the interior articulation bands 158, 178 of the flexible neck assembly 110. Specifically, the reciprocation of the first and second flexible transmission band assemblies 150, 170 in opposite directions causes the interior articulation bands 158, 178 received in the upper and lower slots 120, 121 on the flexible neck segment 111 to reciprocate in a like manner. Upon reciprocation of the interior articulation bands 158, 178, in particular when the first band 158 is moved proximally in tandem with the second band 178 moving distally, the first and second flexible neck portions 114, 116 bend as the neck ribs 118 of the first flexible neck portion 114 move toward each other and the neck ribs 118 of the second flexible neck rib portion 116 concurrently move away from each other. The coupling of the interior articulation bands 158, 178 to the exterior reinforcement band portions 157, 177 of the transmission bands 152, 172, respectively prevents the interior articulation bands 158, 178 from buckling between adjacent neck ribs.

In various arrangements, the distal closure tube segment 190 is slid over the channel guide 128 of the flexible neck assembly 110. The proximal end 191 of the distal closure tube segment 190 has a pair of diametrically opposed slots 192 therein (only one can be seen in FIGS. 1 and 10) for receiving distally protruding lugs 113 protruding from the flexible neck portion 111 to prevent rotation of the distal closure tube segment 190 relative to the flexible neck portion 111. In various embodiments, the distal closure tube segment 190 may be retained on the channel guide 128 by a retention tab (not shown) that extends into the fastener hole (not shown) in the channel guide 128. However, other fastening arrangements may be employed, for example. Such arrangement causes the distal closure tube segment 190 to move axially with the flexible neck assembly 110.

Movement of the first and second transmission bands 152, 172 may be controlled by an articulation transmission assembly 200. The component parts of one form of articulation transmission assembly 200 are illustrated in FIG. 10. In one form, the articulation transmission assembly 200 may include an actuator 210, an articulation body 220 and a nozzle 250 (FIGS. 1 and 13). Rotational movement of the actuator 210 causes corresponding rotation of the articulation body 220 within the nozzle 250. The first and second elongated transmission bands, 152 and 172, consequently reciprocate axially in opposite directions parallel to the longitudinal tool axis LT-LT of the elongated shaft assembly 100 to cause the remote articulation of the end effector 12.

Still referring to FIG. 10, the articulation body 220 has a deck 222 consisting of first and second spaced-apart, semicircular deck halves, 224, 226. The deck halves are mutually opposed to each other and essentially represent mirror images of each other. The first and second deck halves 224, 226 have protruding from their surfaces mutually opposed first and second detents 225, 227, respectively. Each deck half 224, 226 has a set of deck teeth 228 spaced about 180 degrees from the set of deck teeth on the other deck half. The articulation body 220 has a pair of rotation stops 230 protruding from its surface as well as a pair of finger recesses 232. A drive gear 240 protrudes laterally from the articulation body 22. The drive gear 240 has a flared opening 242 through it, and a lateral pivot 244. Within the flared opening 242 of the drive gear 240, there is a firing rod orifice (not shown) for receiving a firing rod 530 therethrough enabling the application of a firing motion to the end effector 12. The drive gear 240 is configured to intermesh with the first and second drive racks 156, 176, respectively to effect the desired reciprocating movement of the first and second transmission bands 152, 172. See FIG. 12.

The nozzle 250 of the articulation transmission assembly 200 may include a nozzle body 252. The nozzle body 252 may have an axial bore 254 therethrough that facilitates the passage of the first transmission band assembly 150 and the second transmission band assembly 170 as well as for the firing rod 530 and other operative components of the instrument 10 including a the proximal end 306 of a proximal outer shaft segment 300. See FIG. 12. The nozzle body 252 may also have a frame groove 256 and flange 258 to rotatably fasten the nozzle body 252 to a housing 400. In various forms, a detent housing 260 comprises a portion of the nozzle body 252. See FIG. 13. An annular array of detent teeth (not shown) is formed within the detent housing 260. A detent housing floor is spaced from the detent teeth. The floor may have a pair of ledges which interact within the rotation stops 230 of the articulation body 220 to limit the degree of rotation. When the articulation body 220 is inserted into the detent housing 260, the base of the articulation body 220 is supported on the floor within the detent housing 260, and the deck teeth 228 of the first and second deck halves, 224, 226 are aligned for meshing engagement with the detent teeth of the detent housing 260. A spring member 268 is supported within the articulation body to bias the deck teeth 228 into meshing engagement with the detent teeth.

Referring again to FIG. 10, the actuator 210 may consist of a lever arm 212, a cap 214 and a pair of retaining fingers 216. The lever arm 212 is mounted on the top of the cap 214. The pair of retaining fingers 216 protrudes laterally from the underside of the cap 214. Each of the retaining fingers 216 has a retaining clip. The retaining fingers 216 are received within the finger recesses 232 of the articulation body 220. First and second detents, 225, 227, on the deck halves of the articulation body are inserted into a slot depression within the underside of the circular cap 214. Advantageously, each of the three significant components of the articulation transmission assembly, namely the actuator, articulation body and nozzle, may be injection molded components. Such components, for example, may be fabricated from a glass fiber-reinforced amorphous polyamide, sold commercially under the trade name Grivory GV-4H by EMS-American Grilon 150.

Ratcheting rotation of the actuator 210 causes articulation of the end effector 12 in the first or second directions relative to the longitudinal tool axis LT-LT. FIG. 4 illustrates the end effector 12 in an unarticulated position in solid lines and exemplary ranges of articulation in broken lines. When the drive gear 240 on the articulation body 220 of the articulation transmission 200 is rotated to thereby drive the first transmission band assembly 150 distally in the “DD” direction and the second transmission bar assembly 170 proximally in the proximal direction “PD”, the end effector 12 will articulate in the first articulation direction “FD” relative to the longitudinal tool axis LT-LT. When the drive gear 240 on the articulation body 220 of the articulation transmission 200 has been rotated to thereby drive the second articulation band assembly 170 in the distal direction “DD” and the first articulation band assembly 150 in the proximal direction “PD”, the end effector 12 will pivot in a second direction “SD” relative to the longitudinal tool axis LT-LT.

As can be seen in FIG. 10, the elongated shaft assembly 100 further includes a proximal outer shaft segment 300 that is attached to the flexible neck assembly 110. The proximal outer shaft segment 300 is substantially rigid and may be attached to the flexible neck portion 111 of the flexible neck assembly 110 by, for example, a press fit, adhesive or other suitable fastener arrangement. As can be seen in FIG. 10, in at least one embodiment, the distal end 302 of the proximal outer shaft segment 300 has a pair of opposed notches 304 therein that are adapted to receive corresponding lugs 115 protruding from the flexible neck portion 111 such that rotation of the proximal outer shaft segment 300 results in rotation of the flexible neck assembly 110 and ultimately of the end effector 12.

Still referring to FIG. 10, the proximal outer shaft segment 300 has a proximal end 306 that has a slot 308 for receiving the drive gear 240 therethrough such that the proximal outer shaft segment 300 may move axially relative thereto. In addition, the proximal end 306 of the proximal outer shaft segment 300 has a flange 310 formed thereon that facilitates rotational attachment to a closure carriage 422 of an actuation system that is operably supported within the housing assembly 400. The closure carriage and actuation system may be of the same or similar type, construction and operation as the closure carriage and actuation system disclosed in U.S. Patent Application Publication No. US 2012/0074200 A1 which has been incorporated by reference herein in its entirety.

Referring now to FIG. 14, the closure carriage 420 may comprise two carriage segments 422 (only one is illustrated) that are interconnected together by adhesive, snap features, screws, etc. As used herein, the term “snap feature” includes, but is not limited to, for example, a tab that has a protrusion thereon that is configured to retainingly engage a corresponding mating portion of another component. Such features may be designed to releasably engage the mating portion or it may not be designed or intended to be removed. In at least one form, the closure carriage 420 has a distal end 424 that has a groove arrangement 426 that is adapted to receive the flanged end 310 of the proximal outer shaft segment 300. Such arrangement serves to attach the proximal end 306 of the proximal outer shaft segment 300 to the closure carriage 420 while facilitating its selective rotation of the proximal outer shaft segment 300 relative to the closure carriage 420. Therefore, the elongated shaft assembly 100 and the end effector 12 that is operably coupled thereto may be selectively rotated about the longitudinal tool axis LT-LT relative to the housing assembly 400.

In various implementations, the housing assembly 400 comprises a pistol-shaped handle housing that may be fabricated in two or more pieces for assembly purposes. For example, the housing assembly 400 as shown comprises a right hand case member 402 and a left hand case member 404 (FIG. 1) that are molded or otherwise fabricated from a polymer or plastic material and are designed to mate together. Such case members 402 and 404 may be attached together by snap features, pegs and sockets molded or otherwise formed therein and/or by adhesive, screws, etc. When assembled, the housing assembly 400 movably supports the closure carriage 420 for selective axial travel therein in response to actuation motions from a trigger, generally designated as 430. As the present Detailed Description proceeds, however, it will be understood that the various unique and novel aspects and attributes of the various implementations of the present invention may be effectively attained when employed with robotically controlled or otherwise remotely controlled systems. Thus, the term “housing” or “housing assembly” may also encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system that is configured to generate and apply at least one control motion which could be used to actuate various forms of surgical end effectors attached thereto. For example, various implementations of the surgical instrument described herein may be used in connection with those robotic systems and arrangements disclosed in U.S. patent application Ser. No. 13/536,323, entitled ROBOTICALLY-POWERED SURGICAL DEVICE WITH MANUALLY ACTUATABLE REVERSING SYSTEM filed Jun. 28, 2012, the entire disclosure of which is incorporated by reference herein.

The trigger assembly 430 may, for example, comprise a primary trigger 440 and a secondary trigger 460. The primary and secondary triggers 440 and 460 are pivotally journaled on a pivot pin assembly 430 formed in the housing assembly 400 such that the triggers 440 and 460 may essentially move relative to each other. Such arrangement permits the trigger assembly 430 to pivot relative to the housing assembly 400 about a pivot axis PA-PA. See FIG. 14. The primary trigger 440 has an elongated, grippable primary trigger paddle 442 that protrudes from a primary drive portion 444 that has a firing rack 446 formed thereon. In one embodiment, the secondary trigger 460 has a secondary trigger paddle 462 that protrudes from a secondary drive portion as discussed in further detail 464 that is pivotally journaled on the pivot pin assembly 430. The primary drive portion 444 has a slot 448 that is adapted to receive the secondary drive portion 464 of the secondary trigger 460 therein as the primary trigger paddle 442 is pivoted towards a pistol grip portion 406 of the housing assembly 400. Such arrangement essentially enables the secondary trigger 460 to “nest” within the primary trigger 440 during actuation. As will be discussed in detail below, the secondary trigger 460 is pivotally actuated by pivoting the primary trigger 440. Thus, in other embodiments, the secondary trigger 460 may lack the secondary trigger paddle 442. In various forms, the trigger assembly 430 may be biased into the unactuated position by a trigger spring (not shown).

As can be seen in FIG. 14, the secondary drive portion 464 of the secondary trigger 460 may have a closure gear segment 466 formed thereon that is configured for meshing engagement with a carriage gear rack 423 formed on the underside of the closure carriage 420. Thus, when the secondary trigger 460 is pivoted toward the pistol grip 406, the closure carriage 420 is driven in the distal direction “DD”.

In various implementations, the actuation system 410 may further include an actuation bar 470. The actuation bar 470 has a first actuation rack 472 formed thereon that is configured for meshing engagement with the primary gear segment 446 on the primary trigger 440. Thus, when the primary gear segment 446 is in meshing engagement with the first actuation rack 472, the actuation bar 470 is driven in the distal direction “DD” when the primary trigger 440 is pivoted toward the pistol grip 406. The actuation bar 470 has a second actuation rack 474 formed thereon configured to meshingly engage clutch teeth 484 on a clutch shaft 482 of a clutch assembly 480. In various embodiments, the clutch shaft 482 is rotatably is supported within the housing assembly 400 and is also laterally movable therein. The clutch shaft 482 has a hub portion 486 that has a plurality of spaced teeth 488 that are configured to drivingly engage teeth openings 492 in a drive gear 490 that is rotatably supported on the clutch shaft 482. The drive gear 490 has a segment of drive gears 494 thereon that are adapted for meshing engagement with a firing rack 500 that is movably supported in the housing assembly 400.

Various embodiments of the clutch assembly 480 may further comprise a clutch plate 510 that is slidably journaled on a clutch pin 449 provided on the primary drive portion 444 of the primary trigger 440. The clutch pin 449 may be movably received within a vertical slot 512 in the clutch plate 510. The clutch plate 510 also has a distally-extending clutch arm 514 that is adapted to actuatably engage a bevel plate 489 formed on the clutch shaft 482. In addition, a clutch spring 520 is employed to bias the clutch shaft 480 laterally such that the teeth 488 on the clutch shaft 482 are brought into meshing engagement with the teeth openings 492 in the drive gear 490.

As can be seen in FIGS. 10 and 14, the firing rack 500 is coupled to a firing rod 530 that is attached to the proximal end of the knife bar assembly 600. In various embodiments, the knife bar assembly 600 may comprise an upper bar segment 602 and a lower bar segment 604. Such arrangement may enable the knife bar assembly 600 to flex as the end effector 12 is articulated, while remaining sufficiently rigid to be driven distally through the shaft assembly 100. In the depicted embodiment, the upper and lower knife bar segments 602, 604 are each attached to an “E-beam” cutting head 610. In the depicted configuration, the E-beam cutting head 610 includes a vertically oriented body portion 612 that has an upper portion 615 and a lower portion 617. A bottom foot 614 is formed on or attached to the lower portion 617. In alternative embodiments, the bottom foot may essentially comprise laterally extending lower tabs that protrude laterally from the lower portion. Similarly, at least one upper tab 616 is formed on or otherwise attached to the upper portion 615 of the vertically oriented body portion 612. In addition, as can be seen in FIG. 2, the vertically oriented body portion 612 further includes at least one intermediate tab portion 618 (only one is shown) as well as a tissue cutting edge 620.

Referring to FIG. 2, the vertically oriented body portion 612 extends through a longitudinally extending slot 622 in the elongated channel 14 and a longitudinally extending slot 624 in the anvil 20. When assembled, portions of the elongated channel 14 are received between the bottom foot 614 and the intermediate tab portions 618. The, upper tab portion 616 is arranged to be received within the anvil 20 above portions 623 of the anvil 20 that define the anvil slot 624. To facilitate ease of assembly, the anvil 20 may be provided with a movable anvil cover 626 and the elongated channel 14 may be provided with a removable channel cover 628. Once assembled, the anvil cover 626 and the channel cover 628 may be installed to prevent tissue, body fluids, etc. from entering the anvil 20 and the elongated channel 14, respectively which may hamper operation of the cutting head 610.

In various arrangements, each staple cartridge 30 includes a cartridge body 31 that has a sled assembly 630 operably supported therein. The sled assembly 630 may have a mounting portion 632 that is configured to extend into a sled slot 613 formed in the vertically oriented body portion 612 of the cutting head 610. See FIGS. 2 and 4. The sled assembly 630 may be configured with wedges 634 that are arranged to contact staple drivers 636 that are operably supported within the staple cartridge 30. The staple drivers 636 may support one or more staples 638 thereon in a known manner. As the sled assembly 630 is driven in the distal direction through the staple cartridge 30, the wedges 632 drive the drivers upward within the cartridge 30 in a known manner. The upwardly moving drivers 636 drive the staples 638 into forming contact with a staple forming undersurface of the anvil 20. The undersurface may, for example, include staple-forming pockets that correspond to each staple.

The end effector 12 may also employ a cutting head lockout system, generally designated as 640 that serves to prevent distal advancement of the cutting head 630 when a new staple cartridge 30 is not present within the elongated channel 14. In at least one arrangement, for example, the cutting head lockout system 640 may comprise a lockout spring 642 that is mounted to the bottom of elongated channel 14. The lockout spring 642 may be configured to contact the bottom foot 614 of the cutting head assembly 610 when the cutting head assembly 610 is in the starting position. See FIGS. 4, 6 and 9. An opening 644 may be provided through the bottom of the elongated channel 14 such that when in that position, the lockout spring 642 biases the bottom foot 614 such that it interferes with the bottom of the elongated channel 14. Thus, when the bottom foot 614 is in that position, if the clinician were to try advance the cutting head 610 distally through the elongated channel 14, the bottom foot portion 614 will contact a portion of the elongated channel 14 to prevent such advancement of the cutting head 610. When a cartridge 30 has been properly installed with the elongated channel 14, the mounting portion 632 of the sled assembly 630 extends into the sled slot 613 and serves to move the cutting head assembly 610 into a position whereby the foot portion 614 is moved out of interfering contact with the bottom of the elongated channel 14. When in that position, the cutting head assembly 610 is free to be advanced distally through the elongated channel 14. Such arrangement serves to prevent the clinician from inadvertently firing the end effector when a new cartridge is not present which could otherwise result in the tissue being cut but not stapled. As the cutting head 610 is advanced distally, the bottom foot 614, the intermediate tab portions 618 and the upper tab 616 cooperate to orient the anvil 20 relative to the staple cartridge deck at a desired spaced relationship relative to each other. A distally presented tissue-cutting edge 620, which is between the upper tab 616 and intermediate tab portions 618, severs clamped tissue while causing the staples 638 within the staple cartridge 30 to be formed into the tissue clamped within the end effector 12.

As can be seen in FIG. 2, the upper firing bar 602 is attached to the upper end portion 615 and the lower firing bar 604 is spaced from the upper firing bar 602 and is attached to the lower end portion 617 of the vertically-extending portion 612 of the cutting head 610. Such arrangement serves to transmit the firing motions to the upper and lower portions of the cutting head 610 in an equivalent manner to facilitate aligned movement of the cutting head through the anvil 20, the surgical staple cartridge 30 and the elongated channel 14. In various arrangements, for example, the upper firing bar 602 may be attached to the upper end portion directly behind the upper tabs(s) such that the upper firing bar 602 is essentially axially aligned with point(s) from which the upper tab(s) protrude laterally from the upper end portion. Similarly, the lower firing bar 604 may be attached to the bottom end portion directly behind the bottom foot or the point(s) from which the laterally protruding bottom tabs protrude laterally from the bottom portion such that the lower firing bar 604 is axially aligned therewith. The upper and lower firing bars 602, 604 may be welded to the vertical extending portion 612 in those locations. For example, the welds may be applied to the firing bars from one side or from both lateral sides of the firing bars. In at least one implementation, the upper and lower firing bars 602, 604 are not directly attached to each other. The portions of the upper and lower firing bars 602, 604 that extend through the elongated shaft assembly 100 to be coupled to a distal end portion 532 of the firing rod 530 are supported in a contiguous orientation relative to each other. The proximal ends of the upper and lower firing bars 602, 604 may be attached to the distal end portion 532 of the firing rod 530 by a coupler member 650. See FIG. 10. As will be discussed in further detail below, the firing rod 530 facilitates the application of firing and retraction motions to the knife bar assembly 600 by the actuation system 410. In at least one implementation, the anvil mounting portion 22 has a wedge-like formation 27 thereon that serves to separate the upper firing bar 602 and lower firing bar 604 as the knife bar assembly 600 is driven in the distal direction “DD”. See, for example, FIG. 9.

In various arrangements, the firing rod 530 extends through a closure bushing 540 that is mounted within the housing assembly 400. In at least one form, a pair of mounting studs 407 protrude from the handle casings 402, 404 and extend through corresponding slots in the closure carriage 420 to be received in a retaining slot in the bushing 540. A closure spring 550 that is attached to a retainer clip 552 is journaled on the closure bushing 540. The closure spring 550 extends between the nozzle body 252 and an internal wall 425 in the closure carriage 420. Thus, the closure spring 550 serves to bias the closure carriage 420 in the proximal direction “PD”.

Various embodiments may also include a releasable closure locking assembly 560 that interfaces with the closure carriage 420 to selectively retain the closure carriage 420 in its distal-most closed or clamped position. In at least one form, the closure locking assembly 560 includes a locking button 562 that is pivotally supported in the housing assembly 400. The locking button 562 has a latch arm 564 that is configured to abut a locking ledge 426 formed on the closure carriage 420 when the button 562 is in the locked position. In addition, the latch arm 564 has a catch 566 formed thereon that is configured to releasably latch with a locking latch 502 on the proximal end of the firing rack 500. A locking spring 568 serves to bias the locking button 562 into the locked position.

Operation of the surgical instrument 10 will now be described. FIGS. 7-9 illustrate the jaws 13 and 15 of the end effector 12 in an open position. When the end effector 12 is in the open position, the latch arm 564 is located on top of the locking ledge 426 formed on the closure carriage 420 such that the catch 566 of the latch arm 564 is in retaining engagement with the locking latch 502 on the firing rack 500. Thus, when in this initial starting position, the knife bar assembly 600 cannot be inadvertently actuated. The clutch plate 510, as well as the closure carriage, are each in their proximal-most unactuated positions. When in those positions, the clutch drive bevel 489 on the clutch shaft 482 is in contact with a portion of the closure carriage 420, which prevents the clutch shaft 482 from laterally moving into meshing engagement with the drive gear 490 under the bias of the clutch spring 520.

To initiate the closure process, a first stroke is applied to the trigger assembly 430. That is, the trigger assembly 430 is initially pivoted toward the pistol grip 406. Such pivoting action serves to drive the closure carriage 420 in the distal direction “DD” by virtue of the meshing engagement between the closure gear segment 466 on the secondary trigger 460 and the carriage rack 423 formed on the underside of the closure carriage 420. Such distal movement of the closure carriage 420 also axially advances the proximal outer shaft segment 300 and the distal closure tube segment 190 in the distal direction “DD”. As the distal closure tube segment 190 moves distally, the pin 19 which extends through the slots 23 in the anvil mounting portion 22, travels from the position illustrated in FIGS. 8 and 9 to the position illustrated in FIGS. 4-6 to pivot the anvil 20 to the closed position. If the surgeon desires to simply grasp and manipulate tissue prior to clamping it between the anvil 20 and the surgical staple cartridge 30, the trigger assembly 430 may be pivoted to open and close the anvil 20 without fully pivoting the trigger assembly 430 to the fully closed position.

Those of ordinary skill in the art will understand that, as the trigger assembly 430 is pivoted toward the pistol grip 406, the actuation bar 470 will necessarily also be driven distally by virtue of the meshing engagement between the primary gear segment 446 on the primary trigger 440 and the first actuation rack 472 on the actuation bar 470. The distal movement of the actuation bar 470 will also result in the an application of a rotary actuation motion to the clutch shaft 482 by virtue of the meshing engagement between the clutch teeth 484 on the clutch shaft 482 and the second actuation rack 474 on the actuation bar 470. However, such rotary motion is not applied to the drive gear 490 because the clutch arm 514 of the clutch plate 510, in contact with the clutch drive bevel 489 on the clutch shaft 482, prevents the axial movement of the clutch shaft 482 into meshing engagement with the drive gear 490. Thus, the clutch shaft 482 freely rotates relative to the drive gear 490. Accordingly, the clutch assembly 480 automatically prevents the activation of the firing rack 500 during the initial actuation of the trigger assembly 430.

Once the trigger assembly 430 has been initially fully compressed into the closed position, the anvil 20 will be retained in the locked or clamped position by the closure locking assembly 560 which prevents the proximal movement of the closure carriage 420. To drive the knife bar assembly 600 distally through the tissue clamped in the end effector 12, the surgeon again pivots the primary trigger 440 toward the pistol grip 406 of the housing assembly 400. As the primary trigger 440 is pivoted, the firing rack 500, the firing rod 530, and the knife bar assembly 600 are driven in the distal direction “DD”. After the knife bar assembly 600 has been driven through the tissue clamped in the end effector 12, the surgeon then releases the primary trigger 440 to thereby permit the primary trigger 440 to pivot to its unactuated position under the bias of the firing spring 432. As the primary trigger 440 pivots back to the starting position, the firing rack 500, firing rod 530, and knife bar assembly 600 are drawn proximally back to their respective starting positions. The end effector 12 remains in its clamped position as shown in FIG. 6. As can also be seen in that Figure, the sled assembly 630 remains in the distal end of the cartridge 30 while the knife bar assembly 600 is returned to the starting position.

To unlock the closure carriage 420 and the secondary trigger 460, the surgeon depresses the locking button 562. As the locking button 562 is depressed, the locking arm 564 is pivoted out of abutting engagement with the locking ledge 426 on the closure carriage 420. Further details regarding the operation of the firing and closure systems may be found in U.S. Patent Application Publication No. US 2012/0074200 which has been herein incorporated by reference in its entirety. As the closure carriage 420 moves proximally, the proximal outer shaft segment 300, the flexible neck assembly 110, and the distal closure tube segment 190 are drawn proximally. As the distal closure tube segment 190 moves proximally, the shaft 19 travels proximally within the slot 23 in the anvil mounting portion 22 to move the anvil 20 to an open position.

As can be appreciated from the foregoing, the various surgical instruments disclosed herein afford the clinician with improved maneuverability and various other advantages that are not available when using prior surgical instruments that are configured to cut and fasten tissue. For example, in various implementations disclosed herein, the end effector is selectively articulatable in the same directions in which the jaws are movable relative to each other. Stated another way, the jaws of the surgical end effector are constrained to move in one plane. In various implementations disclosed herein, the end effector is also capable of moving in that same plane. Prior end effectors are commonly constrained to move in planes that differ from the plane in which the jaws move.

Another advantage provided by many of the present implementations is the use of a firing bar that comprises at least an upper firing bar and at least a lower firing bar that form a laminated structure. The upper and lower bars may at some point be attached to each other or they may be unattached and just be contiguous with each other. In either arrangement, the upper bar is attached to an upper end of the cutting head and the lower bar may be attached to the lower head such that they are spaced from each other at their points of attachment to the cutting head. Such arrangement serves to provide for a more stable cutting head arrangement that may be less likely to twist and/or buckle during actuation. In addition, the cutting head may be equipped with laterally protruding upper tab(s) that engage a portion of the anvil and lower tab(s) that engage the elongated channel. The upper firing bar may be attached directly behind the point where the upper tabs are attached such that it is axially aligned therewith. Likewise the lower firing bar may be attached to the bottom portion directly behind the points where the bottom tab(s) are attached such that it is axially aligned therewith. Such axial alignment facilitates transfer of the driving or actuation motions to the cutting head at the points where the cutting head engages the anvil and the elongated channel which may further prevent and buckling and/or twisting of the cutting head during actuation.

Thus, as can be appreciated from the foregoing, at least one surgical instrument embodiment of the present invention includes an end effector that employs jaws that are selectively movable between open and closed positions by a closure system. The surgical instrument further includes a firing system that is independently actuatable from the closure system for deploying or otherwise actuating a firing member portion of the end effector. The instrument further employs an articulation system that can be used to selectively articulate the end effector in the same directions in which the jaws may move relative to each other.

In one implementation, for example, one of the jaws is configured to operably support a surgical staple cartridge that supports a plurality of surgical staples therein. The surgical staples are supported on drivers that are operably supported within pockets provided in the staple cartridge. A sled assembly is also supported within the cartridge. The sled assembly is configured to operably interface with the firing member of the surgical instrument. The other jaw comprises an anvil assembly that, in at least one implementation, is selectively movable relative to the elongated channel to enable tissue to be clamped between the anvil and the staple cartridge supported in the channel. The movement of the anvil is controlled by the closure system that can be actuated without actuating the firing system. In at least one implementation, the instrument employs one or more lockout arrangements which prevent actuation of the firing system unless the anvil is retained in the closed position.

The firing member in the aforementioned arrangement includes a cutting head that includes a tissue cutting surface or blade. The firing member is supported for distal travel through the surgical staple cartridge upon actuation of the firing system. The cutting head is configured to movably interface with the elongated channel and the anvil to maintain a desired amount of spacing between the surgical staple cartridge and the underside of the anvil as the cutting head is advanced or “fired” from its starting position to an ending position within the surgical staple cartridge. The cutting head is further configured to interface with the sled assembly so that as the cutting head is distally advanced through the staple cartridge, the cutting head moves to the sled assembly with it. As the sled assembly is driven distally through the cartridge, the sled assembly drives the staple drivers upwardly in the cartridge. As the staple drivers move upwardly in their pockets, the staples are driven through the clamped tissue into forming contact with the undersurface of the anvil. After the cutting head has been driven to its end position within the cartridge, the firing system may be used to retract the firing head back to a starting position.

In at least one implementation, the surgical instrument may employ a lockout system that is configured to not only prevent actuation of the firing system or stated another way, advancement of the cutting head through the elongated channel when a cartridge is not present, but also to prevent such firing system actuation unless a new cartridge has been properly supported within the elongated channel. In such implementations, each new cartridge has a sled assembly supported in a starting position. When a cartridge has been properly installed within the elongated channel, the sled assembly interfaces with the lockout system to thereby enable the cutting head to be advanced distally through the cartridge. If, however, a spent cartridge has been inadvertently installed in the elongated channel, the lockout system will prevent actuation of the cutting head, because the sled assembly will be located in the distal end of the cartridge and thereby unable to interface with the lockout system. Such system will prevent re-actuation of the firing system, should the clinician fail to replace a spent cartridge and attempt to actuate the firing system.

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. 

What is claimed is:
 1. A surgical instrument, comprising: a surgical end effector comprising first and second end effector portions wherein the second end effector portion is selectively movable relative to the first end effector portion in a first direction upon application of an opening motion to said second end effector portion, said second end effector portion being further selectively movable in a second direction upon application of a closing motion to said second end effector portion; an elongated shaft assembly defining a longitudinal tool axis and operably coupled to said surgical end effector, said elongated shaft assembly including an articulation portion for facilitating selective articulation of said surgical end effector relative to said longitudinal tool axis in said first and second directions upon application of articulation motions to said surgical end effector; a firing member operably supported for operable movement within said surgical end effector upon application of firing and retraction motions thereto; a firing system configured to selectively apply said firing and retraction motions to said firing member; a closure system configured to selectively apply said opening and closing motions to said first and second end effector portions; and an articulation control system for applying said articulation motions to said surgical end effector.
 2. The surgical instrument of claim 1 wherein said closure system is independently operable from the firing system.
 3. The surgical instrument of claim 1 wherein one of said first and second end effector portions is configured to operably support a surgical staple cartridge therein and wherein said surgical instrument further comprises a lockout system for preventing actuation of said firing system unless said surgical staple cartridge has been installed in said one of said first and second end effector portions.
 4. The surgical instrument of claim 3 wherein said surgical staple cartridge comprises: a cartridge body; a plurality of surgical staples operably supported in said cartridge body; and a sled assembly operably supported in said cartridge body and movable from a first position to a second position within the cartridge body such that said sled assembly causes said surgical staples to be driven from said cartridge body as said sled assembly is driven from said first position to said second position.
 5. The surgical instrument of claim 4 wherein said firing member comprises a cutting head configured to move between a locked position wherein said cutting head is prevented from being distally advanced through said cartridge body and an unlocked position wherein said cutting head is distally advanceable through said cartridge body upon application of said firing motion thereto and wherein said lockout system comprises a biasing member in said end effector for biasing said cutting head into said locked position.
 6. The surgical instrument of claim 5 wherein said sled assembly is configured to bias said cutting head into said unlocked position when said staple cartridge is installed in said one of said first and second end effector portions and said sled assembly is in said first position.
 7. The surgical instrument of claim 1 wherein said firing member comprises: a cutting head comprising: a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end; a bottom foot protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; an upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with said firing system.
 8. The surgical instrument of claim 7 wherein said firing bar assembly comprises: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head.
 9. The surgical instrument of claim 8 wherein said upper and lower firing bars are spaced from each other at their respective points of attachment to the vertically extending portion and remaining portions of said upper and lower firing bars are in contiguous orientation relative to each other.
 10. The surgical instrument of claim 9 wherein said remaining portions of said upper and lower firing bars that are in contiguous orientation relative to each other are operably coupled to a firing rod member of said firing system.
 11. A surgical instrument comprising: a housing; a closure system operably supported by said housing and configured to selectively generate opening and closing motions; a firing system operably supported by said housing, said firing system configured to selectively generate firing and refraction motions; a surgical end effector comprising: an elongated channel configured to removably support a surgical staple cartridge; an anvil movably supported relative to said elongated channel, said anvil movable in a first direction from an open position to a closed position upon application of said closing motion to said anvil, said anvil being further movable from said closed position to said open position in a second direction upon application of said opening motion to said anvil; and a firing member operably supported for operable movement within said surgical end effector upon application of said firing and retraction motions thereto and wherein said surgical instrument further comprises: an elongated shaft assembly defining a longitudinal tool axis and operably coupled to said elongated channel of said surgical end effector, said elongated shaft assembly including an articulation portion for facilitating selective articulation of said surgical end effector relative to said longitudinal tool axis in said first and second directions upon application of articulation motions to said surgical end effector from an articulation system operably supported by said housing.
 12. The surgical instrument of claim 11 wherein said housing comprises a handle.
 13. The surgical instrument of claim 11 wherein said surgical staple cartridge comprises: a cartridge body; a plurality of surgical staples operably supported in said cartridge body; and a sled assembly operably supported in said cartridge body and movable from a first position to a second position within the cartridge body such that said sled assembly causes said surgical staples to be driven from said staple cartridge as said sled assembly is driven from said first position to said second position.
 14. The surgical instrument of claim 13 wherein said firing member comprises a cutting head configured to move between a locked position wherein said cutting head is prevented from being distally advanced through said cartridge body and an unlocked position wherein said cutting head is distally advanceable through said cartridge body upon application of said firing motion thereto and wherein said lockout system comprises a biasing member in said end effector for biasing said cutting head into said locked position.
 15. The surgical instrument of claim 14 wherein said sled assembly is configured to bias said cutting head into said unlocked position when said staple cartridge is installed in said one of said first and second end effector portions and said sled assembly is in said first position.
 16. The surgical instrument of claim 11 wherein said firing member comprises: a cutting head comprising: a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end; a bottom foot protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; an upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with said firing system.
 17. The surgical instrument of claim 16 wherein said firing bar assembly comprises: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head.
 18. A surgical stapling instrument comprising: an elongated channel configured to removably support a surgical staple cartridge; an anvil movably supported relative to said elongated channel; a cutting head comprising: a vertically extending portion including an upper end and a lower end and a tissue cutting portion oriented between said upper end and said lower end; at least one bottom tab protruding from said lower end of said vertically extending portion and configured to movably engage a bottom portion of said elongated channel; at least one upper tab portion protruding from said upper end of said vertically extending portion and configured to engage a portion of said anvil; and a firing bar assembly operably coupled to said cutting head and operably interfacing with a firing system, the firing bar assembly comprising: an upper firing bar segment coupled to said upper end of said vertically extending portion of said cutting head; and a lower firing bar segment coupled to said lower end of said vertically extending portion of said cutting head.
 19. The surgical instrument of claim 18 wherein said upper and lower firing bars are spaced from each other at their respective points of attachment to the vertically extending portion and remaining portions of said upper and lower firing bars are in contiguous orientation relative to each other.
 20. The surgical instrument of claim 19 wherein said remaining portions of said upper and lower firing bars that are in contiguous orientation relative to each other are operably coupled to a firing rod member of said firing system. 